"use client";

import { useState, useId } from "react";
import Link from "next/link";
import { trpc } from "~/lib/trpc/client.js";
import { ProficiencyBadge, PROFICIENCY_LABELS, proficiencyClasses } from "./shared.js";

type SkillRule = { skill: string; minProficiency: number };

interface PeopleFinderTabProps {
  allSkillNames: string[];
  allChapters: string[];
}

export function PeopleFinderTab({ allSkillNames, allChapters }: PeopleFinderTabProps) {
  const datalistId = useId();
  const [rules, setRules] = useState<SkillRule[]>([]);
  const [operator, setOperator] = useState<"AND" | "OR">("AND");
  const [chapter, setChapter] = useState("");

  const activeRules = rules.filter((r) => r.skill.trim().length > 0);
  const { data: results, isFetching } = trpc.resource.searchBySkills.useQuery(
    { rules: activeRules, operator, ...(chapter ? { chapter } : {}) },
    { enabled: activeRules.length > 0, staleTime: 30_000 },
  );

  function addRule() { setRules((prev) => [...prev, { skill: "", minProficiency: 1 }]); }
  function removeRule(idx: number) { setRules((prev) => prev.filter((_, i) => i !== idx)); }
  function updateRule(idx: number, patch: Partial<SkillRule>) {
    setRules((prev) => prev.map((r, i) => (i === idx ? { ...r, ...patch } : r)));
  }

  async function exportXlsx() {
    if (!results || results.length === 0) return;
    const XLSX = await import("xlsx");
    const rows = results.map((p) => ({
      Name: p.displayName,
      EID: p.eid ?? "",
      Chapter: p.chapter ?? "",
      "Matched Skills": p.matchedSkills.map((s) => `${s.skill} (${s.proficiency})`).join(", "),
    }));
    const ws = XLSX.utils.json_to_sheet(rows);
    const wb = XLSX.utils.book_new();
    XLSX.utils.book_append_sheet(wb, ws, "People Finder");
    XLSX.writeFile(wb, `people-finder-${Date.now()}.xlsx`);
  }

  return (
    <div className="space-y-4">
      <div className="bg-white dark:bg-slate-900 rounded-xl border border-gray-200 dark:border-slate-700 p-5 space-y-4">
        <div className="flex items-center justify-between">
          <h2 className="text-sm font-semibold text-gray-800 dark:text-gray-200">People Finder</h2>
          <span className="text-xs text-gray-400 dark:text-gray-500">Find resources that match skill criteria</span>
        </div>

        {/* Datalist */}
        <datalist id={datalistId}>
          {allSkillNames.map((s) => <option key={s} value={s} />)}
        </datalist>

        {/* Rules */}
        <div className="space-y-2">
          {rules.map((rule, idx) => (
            <div key={idx} className="flex items-center gap-2 flex-wrap">
              {idx > 0 ? (
                <button
                  type="button"
                  onClick={() => setOperator((op) => (op === "AND" ? "OR" : "AND"))}
                  className="w-12 text-center text-xs font-bold px-2 py-1.5 rounded-lg border border-brand-200 dark:border-brand-700 bg-brand-50 dark:bg-brand-900/30 text-brand-700 dark:text-brand-300 hover:bg-brand-100 dark:hover:bg-brand-900/50 transition-colors shrink-0"
                >
                  {operator}
                </button>
              ) : (
                <span className="w-12 text-center text-xs font-medium text-gray-400 dark:text-gray-500 shrink-0">knows</span>
              )}

              <input
                type="text"
                list={datalistId}
                placeholder="Skill name..."
                value={rule.skill}
                onChange={(e) => updateRule(idx, { skill: e.target.value })}
                className="flex-1 min-w-40 px-3 py-1.5 border border-gray-300 dark:border-slate-600 rounded-lg text-sm bg-white dark:bg-slate-800 dark:text-gray-200 focus:outline-none focus:ring-2 focus:ring-brand-500"
              />

              <div className="flex items-center gap-1">
                <span className="text-xs text-gray-400 dark:text-gray-500 shrink-0">min.</span>
                <div className="flex rounded-lg overflow-hidden border border-gray-200 dark:border-slate-600">
                  {[1, 2, 3, 4, 5].map((lvl) => (
                    <button
                      key={lvl}
                      type="button"
                      title={PROFICIENCY_LABELS[lvl]}
                      onClick={() => updateRule(idx, { minProficiency: lvl })}
                      className={`px-2 py-1 text-xs font-medium transition-colors ${
                        rule.minProficiency === lvl
                          ? "bg-brand-600 text-white"
                          : "bg-white dark:bg-slate-800 text-gray-500 dark:text-gray-400 hover:bg-gray-50 dark:hover:bg-slate-700"
                      }`}
                    >
                      {lvl}
                    </button>
                  ))}
                </div>
              </div>

              <button
                type="button"
                onClick={() => removeRule(idx)}
                className="text-gray-400 hover:text-red-500 transition-colors p-1"
              >
                <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
                </svg>
              </button>
            </div>
          ))}
        </div>

        {/* Controls row */}
        <div className="flex flex-wrap items-center gap-3">
          <button type="button" onClick={addRule} className="flex items-center gap-1.5 px-3 py-1.5 text-sm rounded-lg border border-dashed border-brand-300 dark:border-brand-700 text-brand-600 dark:text-brand-400 hover:bg-brand-50 dark:hover:bg-brand-900/30 transition-colors">
            <svg className="w-4 h-4" fill="none" viewBox="0 0 24 24" stroke="currentColor">
              <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M12 4v16m8-8H4" />
            </svg>
            Add skill rule
          </button>

          {rules.length > 1 && (
            <div className="flex items-center gap-1.5">
              <span className="text-xs text-gray-500 dark:text-gray-400">Match:</span>
              {(["AND", "OR"] as const).map((op) => (
                <button
                  key={op}
                  type="button"
                  onClick={() => setOperator(op)}
                  className={`px-2.5 py-1 text-xs font-medium border transition-colors ${
                    op === "AND" ? "rounded-l-lg" : "rounded-r-lg -ml-px"
                  } ${operator === op
                    ? "bg-brand-600 border-brand-600 text-white"
                    : "bg-white dark:bg-slate-800 border-gray-200 dark:border-slate-600 text-gray-500 dark:text-gray-400 hover:bg-gray-50 dark:hover:bg-slate-700"
                  }`}
                >
                  {op === "AND" ? "All (AND)" : "Any (OR)"}
                </button>
              ))}
            </div>
          )}

          {allChapters.length > 0 && (
            <div className="flex items-center gap-1.5 ml-auto">
              <span className="text-xs text-gray-500 dark:text-gray-400">Chapter:</span>
              <select
                value={chapter}
                onChange={(e) => setChapter(e.target.value)}
                className="px-2 py-1.5 border border-gray-300 dark:border-slate-600 rounded-lg text-sm bg-white dark:bg-slate-800 dark:text-gray-200 focus:outline-none focus:ring-2 focus:ring-brand-500"
              >
                <option value="">All chapters</option>
                {allChapters.map((c) => <option key={c} value={c}>{c}</option>)}
              </select>
            </div>
          )}

          {results && results.length > 0 && (
            <button type="button" onClick={exportXlsx} className="px-3 py-1.5 text-sm rounded-lg border border-gray-200 dark:border-slate-600 text-gray-600 dark:text-gray-300 hover:bg-gray-50 dark:hover:bg-slate-800 transition-colors">
              Export XLSX
            </button>
          )}
        </div>

        {/* Results */}
        {activeRules.length > 0 && (
          <div className="border-t border-gray-100 dark:border-slate-700 pt-4">
            {isFetching ? (
              <div className="text-sm text-gray-400 animate-pulse">Searching...</div>
            ) : results && results.length === 0 ? (
              <p className="text-sm text-gray-400 dark:text-gray-500 italic">No resources match these criteria.</p>
            ) : results && results.length > 0 ? (
              <>
                <p className="text-xs text-gray-500 dark:text-gray-400 mb-3">
                  {results.length} resource{results.length !== 1 ? "s" : ""} found
                </p>
                <div className="space-y-2">
                  {results.map((person) => (
                    <div key={person.id} className="flex items-start gap-3 p-3 rounded-lg bg-gray-50 dark:bg-slate-800/50 hover:bg-gray-100 dark:hover:bg-slate-800 transition-colors">
                      <div className="flex-1 min-w-0">
                        <div className="flex items-center gap-2 flex-wrap">
                          <Link href={`/resources/${person.id}`} className="text-sm font-medium text-gray-900 dark:text-gray-100 hover:text-brand-600 transition-colors">
                            {person.displayName}
                          </Link>
                          {person.eid && (
                            <span className="text-xs px-1.5 py-0.5 rounded bg-gray-200 dark:bg-gray-700 text-gray-600 dark:text-gray-300">{person.eid}</span>
                          )}
                          {person.chapter && (
                            <span className="text-xs px-2 py-0.5 rounded-full bg-gray-200 dark:bg-gray-600 text-gray-700 dark:text-gray-100">{person.chapter}</span>
                          )}
                        </div>
                        <div className="flex flex-wrap gap-1.5 mt-1.5">
                          {person.matchedSkills.map((s) => (
                            <span key={s.skill} className={`inline-flex items-center gap-1 px-2 py-0.5 text-xs rounded-full border ${proficiencyClasses(s.proficiency)}`}>
                              {s.skill} <span className="font-semibold">{s.proficiency}</span>
                            </span>
                          ))}
                        </div>
                      </div>
                      <Link href={`/resources/${person.id}`} className="text-xs text-brand-600 dark:text-brand-400 hover:underline shrink-0 mt-0.5">
                        View
                      </Link>
                    </div>
                  ))}
                </div>
              </>
            ) : null}
          </div>
        )}
      </div>
    </div>
  );
}